Work resumes at NJ airport site that caught fire

Some operations have resumed at an airport technical center in southern New Jersey, one day after a fire there forced the evacuations of thousands of workers and helped wreak havoc on flights around the country.

But it's still not clear what caused Friday's fire at the technical center at Atlantic City International Airport.

Fire officials say the blaze began on the roof of a center building and then spread inside. No injuries were reported.

The fire made some traffic flow systems unavailable, but didn't affect systems used to directly control air traffic. Traffic flow was moved to a backup system.

Employees at the center were being allowed to return to the site Saturday to collect personal items they left behind during the evacuations.